#!/bin/sh

../../scx <<EOF

,batch on
,open xlib
,batch off

(define (picture point-count)
  (let* ((dpy (open-display))
	 (width 400)
	 (height 400)
	 (black (black-pixel dpy))
	 (white (white-pixel dpy))
	 (root (display-root-window dpy))
	 (win (create-window root width height 
			     'background-pixel white
			     'event-mask '(exposure button-press)))
	 (gc (create-gcontext win
			      'background white 'foreground black)))
    (map-window win)
    (let event-loop ()
      (let ((e (next-event dpy)))
	(if
	 (case (event-type e)
	   ((expose) (begin
		       (clear-window win)
		       (draw-points win gc point-count 0 0 
				    (/ width 2) (/ height 2))
		       (draw-poly-text win gc 10 10 "Click a button to exit"
				       '1-byte)
		       #f))
	   (else #t))
	 #t
	 (event-loop))))
    (close-display dpy)))

(define (draw-points win gc count x y hw hh)
  (if (zero? (modulo count 100))
      (display-flush-output (window-display win)))
  (if (not (zero? count))
      (let ((xf (floor (* (+ 1.2 x) hw ))) ; These lines center the picture
	    (yf (floor (* (+ 0.5 y) hh ))))
	(draw-point win gc (cons (inexact->exact xf) (inexact->exact yf)))
	(draw-points win gc (- count 1)
		     (- (* y (+ 1 (sin (* 0.7 x)))) (* 1.2 (sqrt (abs x))))
		     (- 0.21 x)
		     hw hh))))

(picture 1000)

,exit
y
EOF